Have you heard of knob and tube wiring (also known as K&T)? Whether you are performing home inspections, pest control or wildlife control activities, you face many dangers when inspecting a home. One of the risks that you face is the old-style of electrical wiring, called knob and tube wiring (see image). It essentially involves an electrical copper wire connected to porcelain insulating tubes. According to https://en.wikipedia.org/wiki/Knob-and-tube_wiringWikipedia, knob and tube wiring was used in North American structures from the 1880s up to the 1930s.

Examples of knob and tube wiring — Knob and tube wiring from a Pittsburgh, PA house built in 1930. Photo: Laura Scudder.

What are the risks of knob and tube wiring?

Well, one risk is that you may damage the wiring or break a porcelain tube as you are moving around an attic or crawl space. Unlike, modern wiring, this older form of electrical work exposes its wires so you could catch a cable with your foot or a tool.
Another risk is electrocution. K&T wiring used rubber insulation which would degrade over time. Also frequently, people would modify the wiring in ways that could overload the system. Finally, K&T wiring lacks a grounding wire required in modern wiring.

So if you are inspecting a home built before the 1950s, you will need to ask yourself, “Could this house have knob and tube wiring?” Mindful inspections could save your life. For additional information on inspecting for wildlife damage click, The Wildlife Damage Inspection Handbook, 3rd ed.

Stephen M. Vantassel, CWCP, ACE, is the owner of Wildlife Control Consultant, LLC. He helps people restore their balance with nature through publishing, training, consulting, and the internet. He has published numerous articles in trade and academic publications available at {Stephen’s Academia.edu Page} along with several books {WCC Store}). Listen to his podcast “Living the Wild Life” at {Pest Geek Podcast}. Click the links for past {shows} and {interviews}. Please subscribe to {Stephen’s YouTube Channel} He is a sought after speaker and trainer. If you would like to have Stephen speak at your event or use his consultation services, send an e-mail to [email protected] Copyright All postings are the property of Stephen M. Vantassel and Wildlife Control Consultant, LLC. Text (not images) may be reprinted in non-profit publications provided that the author and website URL is included. If images wish to be used, explicit and written permission must be obtained from Wildlife Control Consultant, LLC.

A Bad Fall: Why NWCOs Can’t Be Too Careful

A friend of mine, let’s call him Kyle, owned a nuisance wildlife control company (NWCO). I write about him because he had a bad fall off a ladder on November 18, 2000. He was inspecting a one floor ranch house for the presence of squirrels in Westerly Rhode Island. Everything was routine. He climbed the ladder and inspected the roof. After completing the roof inspection, he grasped the ladder and placed a foot the rung testing the ladder’s stability. All appeared well so he placed the full weight on the ladder. Regrettably, the ladder’s base kicked out perpendicular from the building. As he started to become horizontal to the ground, Kyle, reached out his left hand in an attempt to grasp the gutter. A bend in the gutter showed he did grab it. But it wasn’t enough to stop his fall. He extended his right hand out to stop his fall. He hit the pavement below with his palm and his right arm fully extended. The resulting force shattered his wrist and elbow. It is the same effect as trying to drive a nail into concrete. It bends. That is what happened to his arm. Fortunately, the owner heard him yelling. A neighbor also saw what happened and drove over to help too. Kyle wondered how he was going to get the ladder on the truck and drive to the hospital.

The result was Kyle getting an external fixater on his forearm which he wore for at least 6 weeks. He also had 2 months of physical therapy. He went back to work 2 weeks after the incident but he was unable to do much work. Most of his time was spent monitoring the people he has had to hire to get the work done. The costs to his business have been substantial. But as Kyle said, “At least this didn’t happen during the Spring.”

I asked Kyle about the cause of this fall. He says, there was no defect in the ladder. He also doesn’t believe the ladder angle was wrong either. He believes the cause was the slick driveway. “It was a very well kept blacktop driveway”. It didn’t rain, but there was dew and wet leaves around. Perhaps, he speculates, leaves got underneath the ladder’s feet. He didn’t tie down the ladder in anyway nor did the ladder have any stabilizers attached. Perhaps his biggest concern is how he will feel climbing ladders again.

Bottom Line

The conclusion of all this is the phrase used on the old series drama, Hill Street Blues. The sergeant always ended the briefing reminding the officers, “You be careful out there”. I couldn’t agree more.

Homeowners should understand that sometimes the least expensive price can be the most expensive. If Kyle wasn’t a stand up guy and someone who cut corners on insurance, then the homeowner may have found himself with a liability lawsuit. Buyer beware.

An earlier form of this article was published in Wildlife Control Technology magazine.

Knob and Tube